Models Show Switch to Bevacizumab, Rituximab Biosimilars Yields Millions in Savings

Cost savings are likely to occur should payers switch from bevacizumab or rituximab to their respective biosimilars, according to research from 2 studies presented at the virtual 2020 International Society for Pharmacoeconomics and Outcomes Research (ISPOR) meeting.

Investigators from India, the United States, and Egypt conducted budget impact analyses to evaluate the potential cost savings from a US payer perspective over 3 years for both bevacizumab and rituximab.

The FDA has approved Zirabev, a bevacizumab biosimilar, for the treatment of non-small cell lung cancer, renal cell carcinoma, glioblastoma, cervical cancer, and colorectal cancer. Zirabev, which is sold by Pfizer and references Avastin, launched in the United States in January. In the first study¹, the population included patients treated with Avastin for approved indications, estimated based on published literature for each year.

In this hypothetical 10 million-member health plan, “503 patients were estimated to be treated with bevacizumab originator or biosimilar in year 1 and 676 patients in year 3.”

They found switching to a biosimilar would save $6827 per patient per year (PPPY) during the first year, marking a total savings of $3,430,967. By the third year, patients would save $20,791 PPPY for a total savings of $14,731,112, authors found. Researchers attributed more than half of the estimated total year 3 savings to patients with colorectal cancer.

Investigators assumed a 70% market shift from Avastin to the biosimilar by year 3 to arrive at their conclusions. They also applied a 20% discount to the biosimilar. When the biosimilar discount was adjusted from 15% to 40%, data showed an average cost savings of $2,573,225 and $6,861,934, respectively, in the first year.

“The results suggest a potential cost saving with switching from bevacizumab originator to bevacizumab-bvzr, driven by lower cost of bevacizumab-bvzr,” authors concluded. However, “the exact cost saving estimates may vary depending on extra drug rebates and proportion of patients switching to bevacizumab-bvzr.”

In an additional study², researchers also modeled a hypothetical scenario of a 10 million-member health plan to assess cost savings of rituximab. The FDA has approved another Pfizer product, the intravenous rituximab biosimilar Ruxience, for the treatment of follicular lymphoma, diffuse large B-cell lymphoma (DLBCL), chronic lymphocytic leukemia, granulomatosis with polyangiitis, and microscopic polyangiitis.

In the analysis, 754 patients were estimated to be treated with reference rituximab, Rituxan, or a biosimilar in year 1 compared with 764 patients in year 3.

Switching to biosimilar rituximab would save individuals $1625 PPPY on average, for a total savings of $1,226,292 in year 1. By year 3, savings were estimated at $4947 PPPY, adding up to $3,779,074. Authors found more than half of the savings were attributed to the DLBCL population.

Similar to the first study, authors applied a 70% market shift from rituximab to the biosimilar, as well as a 20% biosimilar discount. Researchers determined varying the biosimilar discount between 15% and 40% in the first year allowed for a cost savings of $792,865 and $2,960,004, respectively.

Both studies were funded by Pfizer.

References:

1. Ektare V, Liu R, Stephens J, et al. Budget impact analysis of introduction of bevacizumab biosimilar in the United States from a payer perspective. Presented at: ISPOR 2020; May 18-20, 2020; Abstract PB17
2. Ektare V, Liu R, Stephens J, et al. Budget impact analysis of introduction of rituximab biosimilar in the United States from a payer perspective. Presented at: ISPOR 2020; May 18-20, 2020; Absreact PBI17